this is my presentation based on research paper title "Reproductive biology of the milk shark Rhizoprionodon acutus (Rüppell, 1837) from the Gulf of Suez, Red Sea, Egypt"
This was written by Amgad M. Shaaban et al., 2018
Which have Impact factor: 1.98
Ndour et al., 2013. Reproduction of Mugil cephalusIsmaila Ndour
1) The study examined the reproductive parameters of the yellow mullet (Mugil cephalus) on the Northern Coast of Senegal between 2010-2012. 2) It found that the gonadosomatic index and sexual maturity stages peaked in December and January, indicating spawning likely begins in December and is complete by June. 3) The size at first sexual maturity was estimated to be 39 cm for males and 42 cm for females.
Morphological Characteristics and Sexual Maturity in M.masonina, a Freshwater...paperpublications3
Abstract: The present study aims to assess the status of fresh water crab resources in the area. The study was made on species diversity including its taxonomic position, morphological characteristics, habits, habitat and distribution. Out of various water bodies scanned so far two species of crabs were recorded viz Maydelliathelphusa masoniana Henderson, (1893) from plain areas and Himalayapotamon emphysetum Alcock (1909) from hilly stretches of the region. A total of 592 crabs were obtained, 282 being males and 310 females. The maximum carapace in female was 6.0 cm with abdominal width of 4.5 cm. Males exhibited carapace width of 6.3 cm and chela length of 5.7 cm and chela depth of 3.5 cm.
Keywords: M.masoniana, Morphological features, sexual maturity.
Title: Morphological Characteristics and Sexual Maturity in M.masonina, a Freshwater Crab from Jammu Waters
Author: Meenakshi Bandral
International Journal of Recent Research in Life Sciences (IJRRLS)
ISSN 2349-7823
Paper Publications
This research article studied the fecundity and gonado-somatic index of Trichiurus lepturus, an important commercial fish species, along the coast of Zamboanga del Norte, Philippines. The study found that females outnumbered males in the population. Spawning occurred in November and December, as indicated by peak gonado-somatic index values that synchronized with full and new moon phases. Fecundity, or number of eggs produced, was positively correlated with total body length, weight, and ovary weight, with ovary weight found to be the best predictor of fecundity. Understanding the reproductive characteristics of this species can aid in fisheries management.
This document summarizes a study on the reproductive biology of male pipefish (Trachyramphus bicoarctatus) in Lake Qarun, Egypt. The study found that the sex ratio was male to female of 1:1.37, significantly different than the expected 1:1 ratio. Males reached sexual maturity at a length of 7.9cm. Mature males and those brooding eggs were found from December to April. Male fecundity ranged from 42 to 111 eggs and was correlated to fish length. The reproductive period extended from December to April, peaking in February.
This document summarizes the reproductive biology of female Rikuzen sole (Dexistes rikuzenius) based on histological examination of gonads from over 1,000 females collected from 2000-2001. Key findings include:
- Ovulation occurs from September to December, peaking in September-October. Vitellogenesis begins again soon after spawning.
- Maturity is divided into eight phases based on oocyte development stages. Mature ovaries contain developing and postovulatory follicles but no immature oocytes, indicating group-synchronous spawning and multiple spawning per season.
- Almost all females mature at age 1+ and spawn annually until at least age 8+. F
This document summarizes the reproductive biology of female Rikuzen sole (Dexistes rikuzenius) based on histological examination of gonads from over 1,000 females collected from 2000-2001. Key findings include:
- Ovulation occurs from September to December, peaking in September-October. Vitellogenesis begins again soon after spawning.
- Maturity is divided into eight phases based on oocyte development stages. Mature ovaries contain developing and postovulatory follicles but no immature oocytes, indicating group-synchronous spawning and multiple spawning per season.
- Almost all females mature at age 1+ and spawn annually until at least age 8+. F
The fecundity of brackish river prawn (macrobrachium macrobrachion, herklots,...Alexander Decker
I. This study examined the fecundity of the brackish river prawn (Macrobrachium macrobrachion) from the Great Kwa River in Nigeria over a six month period.
II. The number of eggs ranged from 63 to 14,531 with a mean of 4,420.58 eggs per female. Egg diameters ranged from 0.26 to 0.38mm.
III. A strong positive correlation was found between female body size (weight, length, carapace length) and number of eggs. Fecundity increased linearly with body size.
Investigation of otolith in Priacanthus tayenusin persian gulf and Oman SeaInnspub Net
This study aimed to investigation of otolith in Priacanthus tayenusin Persian Gulf and Oman Sea. Sampling lasted from September 2011 to December 2012. During this period 5 samples of Priacanthus tayenus were cut
and studied. Trawling time was 2-2½ hours and trawling depth was considered as 10-100 m daily. Catching and
sampling operations was done within 24 hours. Sampling and catching was done in Khuzestan and Bushehr waters in fall and winter of 2011and since the third week of September 2012 sampling was done in Hormozgan
and Sistan and Baloochestan waters. All thefish were identified and their otolith was extracted to verify them.
Investigation of otolith morphometric characteristics (length, breadth, weight, perimeter and area) were
conducted.
Ndour et al., 2013. Reproduction of Mugil cephalusIsmaila Ndour
1) The study examined the reproductive parameters of the yellow mullet (Mugil cephalus) on the Northern Coast of Senegal between 2010-2012. 2) It found that the gonadosomatic index and sexual maturity stages peaked in December and January, indicating spawning likely begins in December and is complete by June. 3) The size at first sexual maturity was estimated to be 39 cm for males and 42 cm for females.
Morphological Characteristics and Sexual Maturity in M.masonina, a Freshwater...paperpublications3
Abstract: The present study aims to assess the status of fresh water crab resources in the area. The study was made on species diversity including its taxonomic position, morphological characteristics, habits, habitat and distribution. Out of various water bodies scanned so far two species of crabs were recorded viz Maydelliathelphusa masoniana Henderson, (1893) from plain areas and Himalayapotamon emphysetum Alcock (1909) from hilly stretches of the region. A total of 592 crabs were obtained, 282 being males and 310 females. The maximum carapace in female was 6.0 cm with abdominal width of 4.5 cm. Males exhibited carapace width of 6.3 cm and chela length of 5.7 cm and chela depth of 3.5 cm.
Keywords: M.masoniana, Morphological features, sexual maturity.
Title: Morphological Characteristics and Sexual Maturity in M.masonina, a Freshwater Crab from Jammu Waters
Author: Meenakshi Bandral
International Journal of Recent Research in Life Sciences (IJRRLS)
ISSN 2349-7823
Paper Publications
This research article studied the fecundity and gonado-somatic index of Trichiurus lepturus, an important commercial fish species, along the coast of Zamboanga del Norte, Philippines. The study found that females outnumbered males in the population. Spawning occurred in November and December, as indicated by peak gonado-somatic index values that synchronized with full and new moon phases. Fecundity, or number of eggs produced, was positively correlated with total body length, weight, and ovary weight, with ovary weight found to be the best predictor of fecundity. Understanding the reproductive characteristics of this species can aid in fisheries management.
This document summarizes a study on the reproductive biology of male pipefish (Trachyramphus bicoarctatus) in Lake Qarun, Egypt. The study found that the sex ratio was male to female of 1:1.37, significantly different than the expected 1:1 ratio. Males reached sexual maturity at a length of 7.9cm. Mature males and those brooding eggs were found from December to April. Male fecundity ranged from 42 to 111 eggs and was correlated to fish length. The reproductive period extended from December to April, peaking in February.
This document summarizes the reproductive biology of female Rikuzen sole (Dexistes rikuzenius) based on histological examination of gonads from over 1,000 females collected from 2000-2001. Key findings include:
- Ovulation occurs from September to December, peaking in September-October. Vitellogenesis begins again soon after spawning.
- Maturity is divided into eight phases based on oocyte development stages. Mature ovaries contain developing and postovulatory follicles but no immature oocytes, indicating group-synchronous spawning and multiple spawning per season.
- Almost all females mature at age 1+ and spawn annually until at least age 8+. F
This document summarizes the reproductive biology of female Rikuzen sole (Dexistes rikuzenius) based on histological examination of gonads from over 1,000 females collected from 2000-2001. Key findings include:
- Ovulation occurs from September to December, peaking in September-October. Vitellogenesis begins again soon after spawning.
- Maturity is divided into eight phases based on oocyte development stages. Mature ovaries contain developing and postovulatory follicles but no immature oocytes, indicating group-synchronous spawning and multiple spawning per season.
- Almost all females mature at age 1+ and spawn annually until at least age 8+. F
The fecundity of brackish river prawn (macrobrachium macrobrachion, herklots,...Alexander Decker
I. This study examined the fecundity of the brackish river prawn (Macrobrachium macrobrachion) from the Great Kwa River in Nigeria over a six month period.
II. The number of eggs ranged from 63 to 14,531 with a mean of 4,420.58 eggs per female. Egg diameters ranged from 0.26 to 0.38mm.
III. A strong positive correlation was found between female body size (weight, length, carapace length) and number of eggs. Fecundity increased linearly with body size.
Investigation of otolith in Priacanthus tayenusin persian gulf and Oman SeaInnspub Net
This study aimed to investigation of otolith in Priacanthus tayenusin Persian Gulf and Oman Sea. Sampling lasted from September 2011 to December 2012. During this period 5 samples of Priacanthus tayenus were cut
and studied. Trawling time was 2-2½ hours and trawling depth was considered as 10-100 m daily. Catching and
sampling operations was done within 24 hours. Sampling and catching was done in Khuzestan and Bushehr waters in fall and winter of 2011and since the third week of September 2012 sampling was done in Hormozgan
and Sistan and Baloochestan waters. All thefish were identified and their otolith was extracted to verify them.
Investigation of otolith morphometric characteristics (length, breadth, weight, perimeter and area) were
conducted.
This document summarizes the reproductive biology of the flathead grey mullet (Mugil cephalus). Key points include:
- M. cephalus spawns in marine waters from late January to February after migrating from estuaries for spawning.
- Maturity is reached at 16cm length. Gonad development peaks from October to January as indicated by increasing gonadosomatic index values.
- Fecundity ranges from 0.4 to 8.2 million eggs depending on size, with larger fish producing more eggs.
- Sex ratio in spawning stocks favors males at 1.99:1.
Introduction to Tilapia and its meristic charactershajiraali2301
Tilapia is a freshwater fish species that is popular for its mild flavor and versatility in cooking. It is often farmed worldwide due to its fast growth rate and ability to adapt to various environments. Tilapia is low in fat and calories, making it a healthy choice for many diets. It can be grilled, baked, fried, or even used in soups and stews, making it a versatile option for culinary enthusiasts.
Effect of Stocking Density on the Resistance to Fasting, Growth and Survival ...Agriculture Journal IJOEAR
Abstract— After artificial reproduction of African catfish Heterobranchus bidorsalis, larvae of two days old and 2.18 ± 0.35 mg of mean weight were used to perform two experiments in order to assess the effect of stocking density on their fasting resistance, growth and survival. During the first experiment which lasted 11 days with four batches of larvae at densities of 1, 2, 3 and 4 individuals/ml, results showed that density did not significantly affect (p˂0,05) the resistance to fasting of larvae. However, first mortalities were observed at D5 for all the densities, the higher daily mortality was recorded at D10 and the last mortalities were obtained at D12.
Results of the second experiment revealed that the weight and growth performance of larvae decreased with the increasing of the density after 28 days of rearing. In contrast, the larval survival rate increased with the density. The values of survival rate were respectively 30.53 ± 4.32 and 55.30 ± 21.70 % for the densities 1 ind./l and 20 ind./l.
Dive into Ghana's crucial mission of safeguarding sea turtles with this enlightening PowerPoint presentation. Explore the intricate web of challenges these magnificent creatures face and discover their pivotal role in maintaining marine ecosystems. From the impact of climate change to the threats posed by human activities, each slide unveils a facet of the journey toward conservation. Gain insights into ongoing initiatives, community involvement, and innovative approaches to ensure a harmonious coexistence between humans and sea turtles. Together, let's embark on a visual journey to understand the importance of protecting these ancient mariners and fostering a sustainable future for Ghana's coastal biodiversity.
This document reviews Korean hatchery culture techniques for sea cucumbers and their potential application to culturing the local sea cucumber species Cucumaria frondosa in the Northeast U.S. It describes the life history and biology of C. frondosa as well as Korean hatchery facilities, culture tanks, equipment, and techniques for spawning and rearing the Japanese sea cucumber Apostichopus japonicus which could potentially be adapted for culturing C. frondosa.
Morpho-biometric characterization of the indigenous Djallonke sheep in Ngaoun...Open Access Research Paper
In order to study the morpho-biometric characterisation of the indigenous Djallonke sheep Ngaoundere, 126 adult indigenous Djallonke sheep (38 males and 88 females) were sampled from January to December 2020. The results of this study show that the coat colour is dominated by white; the horns, mane and Pendulous are less present; the facial profile is convex and the ears are semi-pendent. In addition, ear length, body length, chest depth, croup length and tail length showed significant differences (p<0.05). The correlation (r=0.844) between the substernal gracility index and the auriculo-thoracic index revealed the existence of sub-populations of indigenous Djallonké sheep that can be the subject of an improvement and preservation programme.
Evidence for impacts by jellyfish on north searatupura
This study examines the potential impact of jellyfish on North Sea herring recruitment. It analyzes data on jellyfish and herring larval abundance in the North Sea from 1971-1986, excluding 1984. The study finds a positive correlation between jellyfish and herring larval abundance, indicating concurrence that could lead to competition. It also finds a negative relationship between survival of herring to age 0 and abundance of the jellyfish Aurelia aurita, suggesting this species may adversely impact herring populations. Finally, the study suggests climate variability, as measured by the North Atlantic Oscillation Index, may influence the impact of jellyfish on herring survival and recruitment through effects on jellyfish abundance.
Study on Production Performance and Economic Benefits between Mixed-sex and M...Premier Publishers
The study was conducted to assess the comparison at the production performance and profitability between mixed-sex and mono-sex tilapia reared in cage culture. The experiment was carried out with two treatments and each was represented by six replicates for a period of 99 days in 12 cages each with the size of 1.5m3 (1.5m×1m×1m) situated in a pond. In the first treatment, six cages of mixed-sex tilapia and in the second treatment, 6 cages of mono-sex male tilapia were stocked. After 99 days of the culture period, mono-sex tilapia attained a significantly higher mean final weight of 189.67 gm ± 19.142 in comparison to mixed-sex tilapia which was 167.15 gm ± 13.297. However, there was no significant difference in food conversion ratio, specific growth rate, and survival rate between the treatments at the end of the study. The benefit-cost ratio was calculated as 1.47:1 and 1.59:1 for mixed-sex and mono-sex male tilapia respectively. The study revealed that there was no significant difference in individual weight, biomass, and the gross yield of tilapia between two treatments up to 72 days of the culture period. The comparative study suggested that within 2.5 months of the culture period, mixed-sex tilapia can be cultured successfully and could be used as an alternative source to the general people who usually avoid the consumption of hormone-treated fish.
Yellowfin tuna are an important commercial fish found worldwide in tropical and subtropical oceans. They form schools and feed primarily on fish, crustaceans, and squids. According to this study, the major components of yellowfin tuna diet were teleost fish, crabs, squids, and shrimps. Overfishing is impacting some yellowfin tuna populations. The study of their feeding habits is important to understand ecosystem impacts and inform sustainable exploitation.
Food and Feeding habits of yellowfin tunaSalmashaik26
Yellowfin tuna are an important commercial fish found worldwide in tropical and subtropical oceans. They form schools and feed primarily on fish, crustaceans, and squids. According to this study, the major components of yellowfin tuna diet were teleost fish, crabs, squids, and shrimps. Overfishing is a concern, as the Eastern Pacific stock is overfished and some overfishing is occurring in the Indian Ocean. The study of their feeding habits is important to better understand their role in the ecosystem and to improve management strategies.
The document summarizes key information about the zebrafish (Danio rerio) including its taxonomy, appearance, distribution, diet, breeding, development, husbandry, history of use as a model organism, and applications in various areas of research such as developmental biology, physiology, toxicology, genetics, and drug discovery. It also discusses zebrafish research centers globally and potential uses of zebrafish in evaluating natural products and toxicity of drugs from Unani medicine.
This document summarizes a study that examined the reproductive biology of barred sand bass off the coast of southern California from June to September 2011. Researchers collected fish and removed and analyzed their gonads histologically to determine spawning characteristics. They found that females spawned for approximately three months during this period. Spawning fraction, interval, and frequency varied monthly, with July having the shortest interval of 1.74 days and highest frequency. This study provides improved estimates of barred sand bass reproductive timing and parameters over the entire spawning season.
The study examined feeding dynamics of juvenile blue crabs (Callinectes sapidus) collected from Florida Gulf waters. Six crabs were fed pieces of fish every 12 hours to determine if feeding time, growth rate, or time of day affected feeding. There was no correlation between growth rate and feeding time or preference for morning vs. night feeding. However, larger crabs consumed food significantly faster than smaller crabs, suggesting intraspecific competition could impact the population based on body size. The flexible feeding behavior allows blue crabs to withstand changes in prey availability.
Growth patterns, sex ratios and fecundity estimates in blue crab (callinectes...Alexander Decker
- The study investigated growth patterns, sex ratios, and fecundity estimates in blue crab (Callinectes amnicola) from Yewa River in southwest Nigeria between June 2011 and May 2012.
- A total of 250 crabs were collected ranging from 5.2-14.8 cm in length and 8.2-165 g in weight. Growth was negative allometric for both sexes. The sex ratio was 1 male to 1.45 females.
- Fecundity estimates ranged from 260,000 to 2,150,692 eggs. Relationships between fecundity and carapace length and weight were determined. The study provides baseline data on the population dynamics of blue crab
ABSTRACT- Order siluriformes, Bagridae family of four number of catfish species provides information on the diets of
Mystus bleekeri, Mystus cavasius, Mystus tengara, Mystus vittatus in Lower Manair reservoir. The total of 1021 fish
species examined and their stomach content was analyzed. The frequency of occurrence and numerical methods were
employed in this study. In the numerical analysis, crustaceans and insect parts (85.91%) constituted the most important
diet of Mystus bleekeri followed by fish remains (78.40%), plant materials (69.01%), algae/ protozoan (64.79%), molluscs
(63.38%), detritus (56.81%) and sand grains (33.80%). The number of food items were enumerated for the crustaceans
and insect parts in Mystus bleekeri have been contained the maximum percentage (34.84%) of the content under
frequency of occurrence method followed by algae and protozoan with 20.76%, Molluscs with 18.37%, plant materials
with 15.60% and sand grains with 10.44%. The result of the analysis showed that Mystus cavasius, Mystus tengara,
Mystus vittatus fed on similar food items. These were mainly crustaceans, molluscans, fish remains and macrophytes.
Other food items include algae, detritus, sand grains. These four species are omnivorous and occupy the same ecological
niche.
Key-words- Cat fish, Food and feeding, Frequency, Numerical method
This study characterized the muscle buffering capacity of three mysticete whale species - gray whales, humpback whales, and minke whales - across different developmental stages. The results showed:
1) Humpback and minke whale calves had lower buffering capacity than adults, suggesting it increases with maturity.
2) Juvenile humpback and gray whales exhibited higher buffering capacity than adults, which may allow them to utilize anaerobic respiration and extend dive durations.
3) Gray whale adults had lower buffering capacity than juveniles, indicating they rely on alternative respiration pathways.
4) Water content analysis validated the buffering capacity results, with no significant differences between species or age classes
Aspects of the biology of african moony, monodactylus sebae from badagry cree...Alexander Decker
The document summarizes a study on the biology of the African moony fish (Monodactylus sebae) in Badagry Creek, Lagos, Nigeria. A total of 267 fish were collected from May 2012 to April 2013. The fish lengths ranged from 56-163 mm and weights ranged from 5.6-151.7 g. The length-weight relationship showed negative allometric growth. The condition factor was higher in females than males. The sex ratio was approximately 1:1 male to female.
A potential endemic cyprinid for aquaculture and food security: The embryonic...AbdullaAlAsif1
The Bornean Spotted Barb is endemic fish species and widely distributed throughout Borneo in various freshwater bodies and can be considered as a potential aquaculture candidate for food security and the ornamental trade. However there has yet to be scientific studies on the early life history and developmental stages of this species. Thus the present study reveals the embryonic development of Puntius sealei embryo, from fertilization to post-hatching using the induced breeding method. The induced spawning on P. sealei using Ovaprim hormone at a dose of 0.5 ml/kg for females and 0.25ml/kg for males respectively was successfully conducted and the embryonic development of the fertilized eggs were observed. The zygote, cleavage, blastula, gastrula, segmentation, and larval phases were the six major stages of embryogenesis that investigated in this experiment. This study contributed major knowledge to the early developmental biology of this particular species. The information will be useful for accessing the potentiality of this species for aquaculture as well as the management, and production of the species.
Population structure, fecundity and morphological characteristics of M. vollenhovenii were studied around Lower Volta River, Ghana subject to dirt of information on this prawn species around the study location. The most prominent morphological characteristics already documented for identification of this species was rostrum bearing 13-15 continuous teeth dorsally and 4-5 teeth on its ventral part. These morphological traits formed the principal components for identification in this study. Results showed that morphological traits on second pereiopods such as presence of spines, spinules, teeth borne within the fingers, and dense projections of setae-like features on telson and uropod were observed relevant for identification purposes. Other results revealed that maximum total length recorded in this study (150-155mm) was higher than total length ranges (≤125mm) documented for this species in earlier studies. Consequently, two adult’s classes of prawns were identified (old adult class 81-120mm; and young adults 31-80mm) and older class was observed to be more in catches than the younger prawns. Absolute fecundity revealed that oocytes estimation varied with respect to seasons, ages of prawns and body sizes of specimens examined. In conclusion, this study observed that M. vollenhovenii fishery is operating in a sustainable manner at the time of this study around the study location.
Brood stock management and induced breeding of Thai Pangus (Pangasius hypopht...AbdullaAlAsif1
The study was conducted on brood stock management and induced breeding of Thai Pangus in a hatchery of Jessore region. Brood fishes were reared in the brood rearing pond by providing artificial diet for good health and full maturation. The water quality parameters; temperature, pH, dissolved oxygen and transparency were recorded from 25-300C, 7-8.5, 4.5-7.1 ppm and 23- 31 cm in the brood rearing ponds respectively. The experiment was conducted on the induced breeding of Pangasius hypophthalmus in a hatchery by using pituitary gland (PG) hormone. The present study consisted of three treatments (TI, T2 and T3) with three replications of each. The eggs and sperms were obtained just by stripping and then fertilization was done by artificial insemination. Nine pairs of male and five pairs of female were selected for induced breeding and the average body wt. of the female and male were 4.47±0.55 kg and 3.65±0.44 kg respectively. To observe the effective dose for induced breeding, the females were injected at the rate of 8 (TI), 10 (T2) and 12 (T3) mg PG/kg body wt. and correspondingly the males were administered a dose of 1 mg PG/kg body wt. in all treatments. The male and female ratio was maintained as 2:1 for each treatment. The fertilization rate, hatching rate, deformity rate and survival rate were determined. The fertilized eggs were hatched within 22-24 hours respectively. The water temperature was recorded between 27 to 28.50C during the experiment period. Among the three treatments T3showed the best result in terms of fertilization rate (87%), hatching rate (82%), deformity of larvae (6%) and survival rate (80%). The present findings can be used in induced breeding of P. hypophthalmus for the development of hatchery propagation. The overall breeding performances of P. hypophthalmus were found to be satisfactory for the commercial production of this fish in Bangladesh.
The anatomy of birds is different to that of most mammals, in a number of immediately obvious ways.
First, they walk on two legs and have two wings. Then, they have feathers instead of hair… and a beak instead of jaws with teeth.
They are warm blooded with a normal body temperature of around 40°C, several degrees warmer than most mammals. They also have two eyes and two ears, though these are not normally visible.
Most birds have little or no sense of smell.
Inventory of Wetlands Fowls by Sana HaroonSana_haroon
This document discusses wetlands, including definitions, classifications, and inventories of wetlands in Pakistan. Some key points:
- Wetlands are areas of land that are covered by water and include marshes, ponds, lakes, rivers, and human-made areas like fish farms.
- Pakistan has over 225 inventoried wetlands located across four major complexes. Several wetlands in Sindh province are recognized internationally under the Ramsar Convention.
- Wetlands provide important benefits and ecosystem services like flood control, water filtration, food sources, habitat, and recreation. Maintaining accurate inventories of wetlands can help with conservation and management efforts.
More Related Content
Similar to Reproductive biology of the milk shark Rhizoprionodon acutus (Rüppell, 1837) by @Sana_Haroon
This document summarizes the reproductive biology of the flathead grey mullet (Mugil cephalus). Key points include:
- M. cephalus spawns in marine waters from late January to February after migrating from estuaries for spawning.
- Maturity is reached at 16cm length. Gonad development peaks from October to January as indicated by increasing gonadosomatic index values.
- Fecundity ranges from 0.4 to 8.2 million eggs depending on size, with larger fish producing more eggs.
- Sex ratio in spawning stocks favors males at 1.99:1.
Introduction to Tilapia and its meristic charactershajiraali2301
Tilapia is a freshwater fish species that is popular for its mild flavor and versatility in cooking. It is often farmed worldwide due to its fast growth rate and ability to adapt to various environments. Tilapia is low in fat and calories, making it a healthy choice for many diets. It can be grilled, baked, fried, or even used in soups and stews, making it a versatile option for culinary enthusiasts.
Effect of Stocking Density on the Resistance to Fasting, Growth and Survival ...Agriculture Journal IJOEAR
Abstract— After artificial reproduction of African catfish Heterobranchus bidorsalis, larvae of two days old and 2.18 ± 0.35 mg of mean weight were used to perform two experiments in order to assess the effect of stocking density on their fasting resistance, growth and survival. During the first experiment which lasted 11 days with four batches of larvae at densities of 1, 2, 3 and 4 individuals/ml, results showed that density did not significantly affect (p˂0,05) the resistance to fasting of larvae. However, first mortalities were observed at D5 for all the densities, the higher daily mortality was recorded at D10 and the last mortalities were obtained at D12.
Results of the second experiment revealed that the weight and growth performance of larvae decreased with the increasing of the density after 28 days of rearing. In contrast, the larval survival rate increased with the density. The values of survival rate were respectively 30.53 ± 4.32 and 55.30 ± 21.70 % for the densities 1 ind./l and 20 ind./l.
Dive into Ghana's crucial mission of safeguarding sea turtles with this enlightening PowerPoint presentation. Explore the intricate web of challenges these magnificent creatures face and discover their pivotal role in maintaining marine ecosystems. From the impact of climate change to the threats posed by human activities, each slide unveils a facet of the journey toward conservation. Gain insights into ongoing initiatives, community involvement, and innovative approaches to ensure a harmonious coexistence between humans and sea turtles. Together, let's embark on a visual journey to understand the importance of protecting these ancient mariners and fostering a sustainable future for Ghana's coastal biodiversity.
This document reviews Korean hatchery culture techniques for sea cucumbers and their potential application to culturing the local sea cucumber species Cucumaria frondosa in the Northeast U.S. It describes the life history and biology of C. frondosa as well as Korean hatchery facilities, culture tanks, equipment, and techniques for spawning and rearing the Japanese sea cucumber Apostichopus japonicus which could potentially be adapted for culturing C. frondosa.
Morpho-biometric characterization of the indigenous Djallonke sheep in Ngaoun...Open Access Research Paper
In order to study the morpho-biometric characterisation of the indigenous Djallonke sheep Ngaoundere, 126 adult indigenous Djallonke sheep (38 males and 88 females) were sampled from January to December 2020. The results of this study show that the coat colour is dominated by white; the horns, mane and Pendulous are less present; the facial profile is convex and the ears are semi-pendent. In addition, ear length, body length, chest depth, croup length and tail length showed significant differences (p<0.05). The correlation (r=0.844) between the substernal gracility index and the auriculo-thoracic index revealed the existence of sub-populations of indigenous Djallonké sheep that can be the subject of an improvement and preservation programme.
Evidence for impacts by jellyfish on north searatupura
This study examines the potential impact of jellyfish on North Sea herring recruitment. It analyzes data on jellyfish and herring larval abundance in the North Sea from 1971-1986, excluding 1984. The study finds a positive correlation between jellyfish and herring larval abundance, indicating concurrence that could lead to competition. It also finds a negative relationship between survival of herring to age 0 and abundance of the jellyfish Aurelia aurita, suggesting this species may adversely impact herring populations. Finally, the study suggests climate variability, as measured by the North Atlantic Oscillation Index, may influence the impact of jellyfish on herring survival and recruitment through effects on jellyfish abundance.
Study on Production Performance and Economic Benefits between Mixed-sex and M...Premier Publishers
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Yellowfin tuna are an important commercial fish found worldwide in tropical and subtropical oceans. They form schools and feed primarily on fish, crustaceans, and squids. According to this study, the major components of yellowfin tuna diet were teleost fish, crabs, squids, and shrimps. Overfishing is impacting some yellowfin tuna populations. The study of their feeding habits is important to understand ecosystem impacts and inform sustainable exploitation.
Food and Feeding habits of yellowfin tunaSalmashaik26
Yellowfin tuna are an important commercial fish found worldwide in tropical and subtropical oceans. They form schools and feed primarily on fish, crustaceans, and squids. According to this study, the major components of yellowfin tuna diet were teleost fish, crabs, squids, and shrimps. Overfishing is a concern, as the Eastern Pacific stock is overfished and some overfishing is occurring in the Indian Ocean. The study of their feeding habits is important to better understand their role in the ecosystem and to improve management strategies.
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ABSTRACT- Order siluriformes, Bagridae family of four number of catfish species provides information on the diets of
Mystus bleekeri, Mystus cavasius, Mystus tengara, Mystus vittatus in Lower Manair reservoir. The total of 1021 fish
species examined and their stomach content was analyzed. The frequency of occurrence and numerical methods were
employed in this study. In the numerical analysis, crustaceans and insect parts (85.91%) constituted the most important
diet of Mystus bleekeri followed by fish remains (78.40%), plant materials (69.01%), algae/ protozoan (64.79%), molluscs
(63.38%), detritus (56.81%) and sand grains (33.80%). The number of food items were enumerated for the crustaceans
and insect parts in Mystus bleekeri have been contained the maximum percentage (34.84%) of the content under
frequency of occurrence method followed by algae and protozoan with 20.76%, Molluscs with 18.37%, plant materials
with 15.60% and sand grains with 10.44%. The result of the analysis showed that Mystus cavasius, Mystus tengara,
Mystus vittatus fed on similar food items. These were mainly crustaceans, molluscans, fish remains and macrophytes.
Other food items include algae, detritus, sand grains. These four species are omnivorous and occupy the same ecological
niche.
Key-words- Cat fish, Food and feeding, Frequency, Numerical method
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3) Gray whale adults had lower buffering capacity than juveniles, indicating they rely on alternative respiration pathways.
4) Water content analysis validated the buffering capacity results, with no significant differences between species or age classes
Aspects of the biology of african moony, monodactylus sebae from badagry cree...Alexander Decker
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Brood stock management and induced breeding of Thai Pangus (Pangasius hypopht...AbdullaAlAsif1
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Reproductive biology of the milk shark Rhizoprionodon acutus (Rüppell, 1837) by @Sana_Haroon
1. Reproductive biology of the milk
shark Rhizoprionodon acutus
(Rüppell, 1837) from the Gulf of
Suez, Red Sea, Egypt
Amgad M. Shaaban et al., 2018
Impact factor: 1.98
Sana Haroon
Synopsis & Research Methodology
2. Introduction
• Chondrichthyan fishes play a crucial functional
role by exerting an effective top–down control on
the function and structure of coastal and oceanic
ecosystem (Heithaus et al., 2012).
• Therefore, declines in shark populations can lead
to cascading effects in ecosystems (e.g., reduction
of commercial scallops in northeast Atlantic,
Myers et al., 2007).
3. Conti..
• These fishes are incidentally caught as bycatch in
many fisheries (Dulvy et al., 2014).
• Globally, more than 700,000 tons of Chondrichthyan
fishes are catched annually (Frisk et al., 2001).
No previous studies have been conducted on the milk
shark, Rhizoprionodon acutus, from the Gulf of Suez.
4. Conti..
• The milk shark, Rhizoprionodon acutus, is a species of
requiem shark, and part of the family Carcharhinidae,
whose common name comes from an Indian belief
that consumption of its meat promotes lactation.
• Of the seven species of the genus Rhizoprionodon,
Rhizoprionodon acutus has the widest geographic
distribution that occurs from West Africa to the
western Pacific (southern Japan) (Compagno, 1984).
5. Conti..
• The International Union for Conservation of
Nature (IUCN) has listed the milk shark under
least concern; despite being heavily fished, it has a
wide distribution and remains fairly common
(Simpfendorfer, 2003)
6. Conti..
• The paucity of biological data for most shark species
constitutes a barrier for the determination of their
specific susceptibility to overexploitation and has
subsequently obstructed the efforts made for shark
management and conservation (Frisk et al., 2001).
• Therefore, the gathering of biological data should be
a crucial element for biologists, fisheries scientists and
resource managers (Cope, 2006).
7. Conti..
• The periodicity and success of reproduction in
fish can be affected by
Growth rates
the availability of mates
resource competition, food availability
the removal of individuals
(Pianka, 1970; Winemiller, 2005)
8. Aims & Objectives
• Aim: These data will be useful for designing effective
management strategies for shark fisheries and consequently help
in the conservation of sharks.
• Objective: To study
sexual maturity in males & females
Gonadosomatic (GSI) and hepatosomatic (HSI) indices
Biological traits of females
Embryonic development and gestation
Fecundity
Sex ratio
9. Hypothesis & Impact factor
• To study the life history traits of this species by investigating
the length at 50% maturity
the length at birth
the ovarian and uterine fecundities
the reproductive cycle.
• Egyptian journal of aquatic research impact factor = 1.98
10. Materials and methods
• The study area
The Gulf of Suez (Fig. 1) is a large semi-closed
area of a length extends about 346 km. The
average width is about 54.2 km and mean depth
of about 40 m. The total surface area of the Gulf
of Suez is about 10,510 km2 (Hamed and Emara,
2006).
11.
12. Conti..
• Sampling and data collection
Shark specimens were collected from the
commercial trawling and artisanal fisheries
operating in the Gulf of Suez. A total of 357 R.
acutus (Table 1) were collected between October
2012 and December 2015 from the Ataka landing
site in Suez City (Long, 32 34/ E, Lat, 29 56/N).
14. Conti..
a. Sex was recorded
b. Total length (TL) was measured to the nearest millimeter from
the tip of the snout to the end of the upper lobe of the caudal
fin.
c. Total body weight (TW) was measured to the nearest gram.
d. According to Collenot (1969), the claspers inner length (CLI)
was measured from the forward rim of the pelvic girdle to the
distal edge of the claspers to the nearest millimeter.
15. Conti..
• Male reproductive systems were investigated to
assess the status of the testes and seminal vesicles.
• Testes were isolated from the epigonal system and
weighed to the nearest 0.1 g.
• Calcification of claspers, the condition of the testes
were reported to assess the maturity stage according
to Henderson et al. (2006), maturity scale (Table 2).
16. Conti..
• Female reproductive systems were inspected for determination of
the maturity stage according to Henderson et al. (2006), maturity scale
(Table 2).
• The number and diameter of developing and ripe follicles were
recorded.
• The number, the total length and total weight of developing and near-
term embryos were recorded.
• Embryos were sexed when possible.
• The oviductal gland weights were recorded to follow up their changes
throughout different maturity stages.
18. Results
Sexual maturity in males
•The smallest recorded male was 44.6 cm TL
and 376 g TW.
•While the largest male measured 88.5 cm TL
and 2995 g TW.
•The smallest estimated mature male measured
70.4 cm TL,
•while the largest immature male was 79.8 cm
TL.
•The length at 50% maturity for males was
estimated to be 76.5 cm
19. Sexual maturity in females
• The smallest recorded female was 47.8
cm TL and 421.7 g TW,
• while the largest female was 97.2 cm
TL and 4355 g TW.
• However, the smallest mature female
was 73.1 cm TL and 1770 g TW,
• the largest immature female was 78 cm
TL and 2093 g TW.
• The estimated TL at 50% maturity or
the length at first maturity was
estimated to be 74 cm
20. Embryonic development and gestation
• The embryonic development after the depletion of the yolk sac, is
through placenta.
• A total of 116 embryos were contained in the 39 gravid females,
comprising 56 males, 55 females and 5 undifferentiated ones.
• The smallest embryos were 7 and 8.7 cm TL and weighted 1.8 and 2.7
g respectively, while the largest embryo was 39.5 cm TL, which
weighted 259 g.
• The length frequency of R. acutus embryos showed a normal
distribution pattern (Fig. 11).
• The smallest individual collected during the study was 44.6 cm TL and
376 g TW.
• Based on the near-term embryos and neonates, the length at birth
ranged from 39.5 to 44.6 cm (mean 42.05 ± 2.55) and the weight
ranged from 259 to 376 g (mean 317.5 ± 58.5).
21.
22. Gonadosomatic (GSI) and hepatosomatic
(HSI) indices
• The gonadosomatic index for males and females varied
seasonally with a peak in summer but with no significant
difference among seasons (ANOVA, d.f. 3 and 74, p = 0.66 for
male and d.f. 3 and 107, p = 0.29 for females) (Fig. 8).
• However, the hepatosomatic index of males and females
exhibited the same pattern of variation in which there is a
decrease of the HSI in summer but with a significant difference
among seasons (ANOVA, d.f. 3 and 102, p = 0.01 for males and
d.f. 3 and 133, p = 0.003 for females) (Fig. 9).
23.
24. Conti..
• The gonadosomatic index (GSI) and
heptosomatic index (HSI) were estimated as
indicators of the reproductive cycle for males and
females.
GSI ¼ ½ weight of the gonad=whole body weight 100
HSI ¼ ½ weight of the liver=whole body weight 100
25. Conclusion
• The milk shark, Rhizoprionodon acutus, in the Gulf of Suez
appear to reproduce throughout the year with a peak in summer
(partially seasonal reproductive cycle).
• The vitellogenesis and embryogenesis occur concurrently with
no resting period between parturition and ovulation and there is
no distinct parturition season.
26. Future perspective
• To design effective management strategies for shark fisheries
• To help in the conservation of sharks.
27. References
• Ba, A., Ba, C.T., Diouf, K., Ndiaye, P.I., Panfili, J., 2013. Reproductive biology
of the milk shark Rhizoprionodon acutus (Carcharhinidae) off the coast of
Senegal. Afr. J. Mar. Sci. 35, 223–232.
• Bass, A.J., D’Aubrey, J.D., Kistnasamy, N., 1975. Sharks of the east coast of
southern Africa. 3. the families Carcharhinidae (excluding Mustelus and
Carcharhinus) and Sphyrnidae. investigational report. Oceanogr. Res. Inst.
Durban 38, 4–100.
• Cadenat, J., Blache, J., 1981. Requins de Méditerranée et d’Atlantique (plus
particulièrement de la cote occidentale d’Afrique). (Sharks from the
Mediterranean and Atlantic [especially from the western coast of Africa]).
Faune Tropicale Series 21. Paris, ORSTOM.
• Capape, C., Diatta, Y., Diop, M., Guelorget, O., Vergne, Y., Quignard, J., 2006.
Reproduction in the milk shark, Rhizoprionodon acutus (Rüppell, 1837)
(Chondrichthyes: Carcharhinidae), from the coast of Senegal (eastern tropical
Atlantic). Acta Adriat. 47, 111–126.
28. • Capapé, C., Diop M. and N’dao M., 1994. Observations sur la biologie de la
reproduction de dix-sept espèces de Sélaciens d’intérêt économique captures
dans la région marine de Dakar-Ouakam (Sénégal, Atlantique oriental
tropical). (Observations on the reproductive biology of seventeen species of
economical interest captured in the marine area of Dakar-Ouakam [Senegal,
Eastern Tropical Atlantic]) Bulletin de l’Institut Fondamental d’Afrique Noire
A. vol. 47 pp. 87–102
• . Castro, J.I., 1996. Biology of the blacktip shark, Carcharhinus limbatus, off
the southeastern United States. Bull. Mar. Sci. 59 (3), 508–522.
• Collenot, G., 1969. Eutude biome´trique de la croissance relative des pte´
rygopodes chez la roussette Scyliorhinus canicula (L.). Cah. Biol. Mar. 10,
309–323. Compagno, L.J.V., 1984. FAO species catalogue. vol. 4 sharks of
the world. anannotated and illustrated catalogue of shark species known to
date. part 2. Carcharhiniformes. FAO Fish. Synop. 4 (2), 251–655.
29. • Compagno, L.J., 2001. Sharks of the World: An Annotated and Illustrated
Catalogue of Shark Species Known to Date (Vol. 1). Food & Agriculture Org.
• Cope, J.M., 2006. Exploring intraspecific life history patterns in sharks. Fish.
Bull. 104, 311–320.
• Craik, J.C.A., 1978. An annual cycle of vitellogenesis in the elasmobranch
Scyliorhinus canicula. J. Mar. Biol. Assoc. U.K. 58, 719–726.
• Devadoss, P., 1988. Observations on the breeding and development of some
sharks. J. Mar. Biol. Assoc. India 30, 121–131.
• Dulvy, N.K., Fowler, S.L., Musick, J.A., Cavanagh, R.D., Peter, M., Kyne, L.R.H.,
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Editor's Notes
Chondrichthyes= is a class that contains the cartilaginous fishes; they are jawed vertebrates with paired fins, scales, a heart with its chambers in series
cascading= to fall or pour
Trawling= drag/ collect fish
Artisanal= a product/food made in traditional way or non-mechanized way
Epigonal system= epigonal organ; elomgate paired tissue partially envelope the anterior gonads, important to immune system
Gravid female= carrying eggs or young; pregnant
Neonates= a new born child( infant less tha 4 weeks old)
Vitellogenesis (yolk deposition)=process of yolk formation via nutrients being deposited in the oocyte or female germ cell is involved in reproduction of lecithotropic organisms.
Parturition=birth time period